The present invention relates generally to cells that produce pseudotyped retroviruses having broad host range. Specifically, the invention relates to cells that produce retroviruses pseudotyped with glycoproteins derived from either filoviruses or viruses having at least two different viral glycoproteins disposed in their lipid bilayer. The invention further relates to methods of producing such cells, the pseudotyped retroviruses produced, methods of making and using the pseudotyped retroviruses and kits for producing the pseudotyped retroviruses.
Retroviruses are ribonucleic acid (RNA) viruses that include an RNA genome enclosed within a viral capsid wherein the capsid is surrounded by an envelope, or lipid bilayer. Glycoproteins present in the lipid bilayer (envelope glycoproteins) interact with receptors on the surface of various host cells and allow the retroviruses to enter the host cell. Once in the cell, the retroviruses reverse transcribe the RNA of the viral genome into a double-stranded DNA (a proviral intermediate), and incorporate the deoxyribonucleic acid (DNA) into the cellular genome as a provirus. Gene products from the integrated foreign DNA may then be produced so that progeny viral particles may be assembled. As retroviruses can be modified to carry exogenous nucleotide sequences of interest, such recombinant retroviruses have a variety of uses. For example, such recombinant retroviruses are important in introducing desired exogenous sequences into a cell, so that relatively high levels of the protein encoded by the sequences may be produced. However, use of such recombinant retroviruses has several drawbacks.
For example, retroviruses do not have a broad host range. Efforts at increasing the host range of retroviruses have included substituting the envelope glycoproteins of the virus with that of a different virus, thus forming a pseudotyped retrovirus. The pseudotyped retrovirus advantageously has the host range of the different virus. However, some retroviruses have been pseudotyped with viral glycoproteins that are toxic to cells, so the cells can only produce the virus for a limited time. Furthermore, in many cases, the pseudotyped retroviruses can not be stably produced and may not be produced at a high titer.
There is therefore a need for pseudotyped retroviruses of broad host range, and cell lines capable of producing such pseudotyped retroviruses. The present invention addresses this need.